Photoelectric sizing and sorting apparatus



United States. Patent Patented PHOTOELECTRIC SIZING AND SORTING APPARATUS 5 Claims, 4 Drawing Figs.

U.S. Cl. 209/82, 209/ l l 1.7 Int. Cl. 1307c 5/10 Field of Search 209/74, 82, 111.6, 111.7

References Cited UNITED STATESPATENTS 3,153,727 1011964 Nathan 209/111.7X 3,327,850 6/1967 Simmons 209/11 1.7

3,349,905 10/ l 967 Crawford ABSTRACT: A sorting apparatus is disclosed for sorting consecutively delivered articles according to a selected criteria. Photoelectric scanning components are disposed on opposite sides of the articles path and adjacent the end of article conveyor means. The articles to be sorted are consecutively ejected from said means at a speed whereby they will follow a path or trajectory past said scanning components. Nozzles for directing an air blast at said article are located immediately downstream from said scanning components and are in communication with air solenoid valves which upon activation release a directed air blast to divert an article from its path into receiving means for that particular size of article. The scanning components are in circuit with lock out and lock in switches and with logic modules to activate the required solenoid valve for a desired dwell period.

PATENTEUBE022|970 $549,008

SHEET 1 0F 2 IN VENTOR. RONALD L. ANDERSON AGENT PATENTED DEE22 I970 SHEET 2 [IF 2 AGENT PI-IOTOELECT RIC SIZING AND SORTING APPARATUS BACKGROUND OF THE INVENTION v blast to divert the objects into receiving means according to their size.

The art I am aware of discloses other sorting apparatuses utilizing a directed blast of air triggered by photoelectric scanning means to divert the objects being graded. Such apparatuses are associated with and dependent upon the object being carried upon an endless belt during both scanning and sorting operations. The object sorted by prior art devices is usually produce and is laterally displaced from its course in a horizontal plane while being supported on a belt or belts. Sorting movement is limited since the articles may be diverted only to the right or the left or lastly, permitted to follow a straight course and further such sorting movement is slowed by friction of the supporting belt.

While the foregoing art may be advantageously used in some types of produce sorting operations it is not practical in a high speed sorting operation and wherein sorting is into several classifications. Further, by reason of the object being supported upon an endless belt while it is being diverted the time required to divert the article severely limits the rate at which sorting may be accomplished.

A further disadvantage of those sorting apparatuses utilizing a scanning system for articles on a belt conveyor is that in scanning over or through pair of belts, water particles and foreign debris on the belts may trigger a false signal. The instant sorting apparatus incorporates a photoelectric scanning system disassociated or removed from the article delivery means resulting in water or foreign particles being disposed of prior to the light sources and photocell receivers of the scanning system.

As an important advance in the present art the herein disclosed apparatus accomplishes the sorting of successive objects while each of said objects is in a trajectory after discharge from a conveying means. Accordingly the article may be acted upon by one of a multitude of air blasts nozzles to divert same from its course into a receptacle or collecting means for that particular size of article.

Of additional importance is the increased sorting rate achievable by the present system wherein the object is deflected while in flight. In previous arrangements the supporting belt offers frictional resistance to the diverting of the article into a new course. The present apparatus succeeds in rapidly sorting articles without the hindrance of belts in the sorting area or impediment of sorting movement by a belt. Secondly the air blast force required may be of less magnitude and for a shorter duration since only the articles course is being altered in comparison with existing sorters wherein the article is physically moved by the blast onto a second laterally disposed belt.

The present invention may further include the use of a target to receive the articles being sorted, the article ultimately being deposited according to its classification into a receptacle or onto further conveying means.

SUMMARY Briefly, the present invention is embodied within the concept of an apparatus for the photoelectric scanning of consecutively passing articles to be sorted and subsequently diverting the article according to a criteria thereof while the article is in a flight trajectory.

The above advantages are realized by a novel circuit having lockout and lock in switches actuated by the scanning components and controlling the operation of valves associated with air noules disposed adjacent the path traversed by successive articles being graded. Only the inertia of each article need be partially overcome with no frictional resistance of a supporting belt being present.

The scanning components consisting of paired photoelectric cells and light sources are disposed along the articles path. A main photoelectric control unit is controlled by the initial pair of scanners and through lock out switches in the circuit prevents any air blast from being triggered until the article has entirely passed by the main beam of said unit. After passage of the articles trailing end past the beam of the main control unit the next beam interrupted by the leading edge of the article will cause a lock in switch to close which switch completes a circuit to an air solenoid valve for the diverting air blast.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings;

FIG. 1 is a view showing in side elevation the general physical arrangement of mechanical and photoelectric scanning components of the present invention,

FIG. 2 is an isometric view of article receiver means to conduct the sorted article to additional conveying or receptacle means not part of the present invention,

FIG. 3 is an electrical schematic of the circuitry for the present invention,

FIG. 4 is a composite view of five examples each showing articles of different lengths and in relation to photoelectric beams of the apparatus.

DESCRIPTION OF PREFERRED EMBODIMENTS With continuing reference to the drawings wherein like reference numerals indicate like parts similarly identified in the following specification the reference numerals 10, 11, 12, 13 and 14, FIG. 1 indicate a series of individual light sources of a photoelectric scanning system. Reference numerals l5, 16, 17, 18 and 19 photocell receivers each operative respectively in cooperation with its above identified light source. Each light source and its receiver are operable with a photoelectric control unit later described.

Mounting plates at 20 and 21 may be provided with an elongated slot (not shown) to enable the light sources l0-l4 and the photocell receivers 1519 to be adjustably mounted whereby the lateral horizontal distance as viewed in FIG. 1 between each of said sources and each of said receivers may be varied as later elaborated upon. Further the mounting plates themselves should be capable of independent vertical positioning. The light sources and photocells are oppositely spaced from a path indicated at P of consecutively delivered articles to be sorted.

In the drawing vegetable produce in the form of a miniature carrot is shown at 22 such being discharged from conveyor means at a speed sufficient to provide the necessary momenturn for the following described grading or sorting operation. Conveyor belt at 23 and 24 are shown disposed in a V to carry the carrot on the marginal portions of the belts at the bottom of the V. Belt speed will vary depending on the nature of the article being processed but in any event the required speed for imparting the necessary momentum is within the capability of existing conveyor systems. The close proximity of the entire photoelectric scanning system to the conveyor means is desirable for the reason that the articles paths will be nearly identical. Where very small articles of light weight are being sorted it is to include a hold down belt narrow in section to ride upon the bottom adjacent portions of belts 23-24 and overly the articles thereon. Said belt would have a lesser speed than belts 23-24 due to slippage. Such belts are made and sold by Urschel Mfg. Co.,. The advantages of the scanning system being offset from the conveyor end have been previously set forth.

An exemplary set up for sorting produce in the form of miniature carrots (ranging approximately from it to 3 inches in length) may entail the scanning system components being located along opposite sides of the articles path P with the outermost or end pair of light source and photocell receiver being within a foot or so from the belt conveyor end. This distance will obviously be subject to variation for sorting articles of other median lengths. While the present description has and will hereinafter refer to a particular article being sorted it is believed readily apparent that the present sorting system may be obviously adapted to the sorting of various articles according to a selected criteria with but minor variations in components and their arrangement.

lndicated at 25, 26, 27 and 28 are a plurality of nozzles each associated with a solenoid air valve later described. A momentary, directed air blast from one of said nozzles may be impinged against each passing article to divert same. Each air nozzle is in solenoid valve controlled communication with a source of air pressure whereby upon a signal, initiated by the scanning system, a solenoid valve operable in conjunction with one air nozzle will be actuated to release said air blast to divert said article from its normal trajectory or path.

The circuitry and associated components for scanning, measuring and sorting are hereinafter described.

Each light source is in circuit with a source of electrical energy and is of the type projecting a sharply focused beam onto its corresponding receiver both being in circuit with a photoelectric control unit. A main photoelectric control unit is at 29 having a chassis with a logic module LMl in circuit with the photocell 15. An 18 Volt DC power source powers the chassis 29, a logic module LM] and three main switches 30, 31 and 32. Each of said main switches including respectively a single pole 33, 34 and 35 with switch 30 being a double-throw switch and switches 31-32 being single throw. While mechanical type reed switches are satisfactory and are shown at 30-32 as relays and like components are similarly shown throughout the remaining circuit it will be understood that transistorized switches having solid state contacts are preferred for their extremely fast switching times of less than 20 microseconds and their long life. The transistorized components preferred are sold under the trade name Sincos by the Farmer Electric Products Co., Inc. Their use in place of relays and reed type switches throughout the following described circuit is preferred. These switches are commercially available with one set of normally open and one set of normally closed contacts. One or both sets of contacts may be used.

The 18 Volt DC power source is in circuit with the poles 33- -35 of each of said switches 30-32 by conductors 48, 36. The control circuit of each above switch, shown as a coil, is supplied with current by wire 37 through which a signal from the main control 29 is transmitted.

Circuits at C1, C2, C3 and C4 will now be described each of said circuits having the ultimate function of actuating an air valve therein for diverting by air blast the article being graded. For convenience the circuits are referred to as number C1, C2, C3 and C4 starti ng immediately downstream (direction travelled of articles being graded) to the last circuit at the right hand side of FIG. 3. With regard to the last circuit C4 a pair of lockout relays are not included since same are not required in connection with the operation of the solenoid air valve therein.

Each circuit C1-C4 include the aforementioned paired scanning components hereinafter referred to as secondary components 11, 16; 12, 17; 13, 18 and 14, 19 respectively and each of said components are in circuit with the chassis of secondary photoelectric control units 40, 41, 42 and 43. While the circuits shown and described show leads for the light sources originating in said control units they may be supplied through a noninterruptable source for continuous operation. These control units will now be described to the extent necessary keeping in mind that suitable photoelectric control units are commercially available. Specifically a suitable photoelectric control unit is also manufactured and sold by Farmer Electric Products Co., Inc., and is identified as a TRB transistorized photoelectric control. The control unit for each circuit C1-C4 includes a chassis which mounts terminals for leads associated with that circuits scanning components and a transformer which is not used by reason of a 18V power source being provided. Each chassis further receives a plug in type logic modules LM2, LM3, LM4 and LM and a solid state single pole, single throw switch at 44, 45, 46 and 47 of the type previously described at 31-32. Switches 44-47 are hereinafter referred to as secondary control unit operated switch means.

Logic modules as known in the art include means responsive to the scanning signals for triggering an impulse which is lengthened or stretched" by adjustable means also conventionally provided in the module and thereby lengthened into a dwell period from 10 to 250 milliseconds. Such a module is also manufactured and sold by the aforementioned company being further identified as a TR4 high speed impulse type and settable to operate on dark or light i.e., interruption or reestablishment of the light beam the former being utilized in the present system. Accordingly the switches 44, 45, 46 and 47 may each be held in an activated position for a duration within the millisecond range above noted the starting point of the duration being when the articles leading edge interrupts the light beam of the scanning components associated with its particular module. The dwell time capability of the module is utilized both to provide a period of time during which the air blast from air valves will be discharged for diverting of the graded article and to deactivate other secondary photoelectric control units. Since the modules are an off-the-shelf readily available component no explanation of their circuitry is believed necessary.

For purposes of description the beam of the main unit 29 is identified as MB with the downstream beams consecutively indicated at B1, B2, B3 and B4.

In each circuit C1, C2, C3 and C4 is a lock in switch 51, 52, 53 and 54 respectively so termed for their function of actuating or locking in the solenoid operated air valve in each circuit. The lock in switches are double-throw single-pole and of the same switch type previously described. A source of power is provided, in series, to the pole and normally closed contact of each of said lock in switches by the conductor 48. Leads 49 branch off from each of the conductors 48 to provide the secondary control units 40-43 with a source of power.

Included within each of the circuits C1, C2, and C3 are a pair of lockout switches one normally closed and one normally open identified at 55-56; 57-58 and 59-60. Again these last mentioned switches are of the type previously described in regard to the switches in circuit with the main photoelectric control 29 and the lock in switches just described. The C1 lockout switches have single poles indicated at 62 and 63 and each switch having a single contact 64 and 65. C2 lockout switches 57 and 58 have poles 66 and 67 with contacts at 70 and 71. C3 lock out switches 59 and 60 have poles 72 and 73 with contacts at 74 and 75. As above noted lockout switches 55, 57 and 59 are normally closed while the remaining lockout switch in each pair is normally open. The control circuit of each switch shown in FIG. 3 is shown by a coil symbol.

A conductor 76 provides the poles of normally closed lockout switches 55, 57 and 59 with a source of power such being provided through the pole33 of main switch 30 in its normal position against contact 77. Conductor 76 terminates at the pole of secondary control unit actuated switch 47 in circuit C4.

The opposite contact 78 in switch 30 is in circuit via a wire 79 with the control circuits (shown as coil symbols) of the C1 lockout switches 55 and 56 and by wire 84 with the pole 63 of the latter switch.

The control circuits in the lockout switches 57 and 58 of C2 are put in communication with a source of power by wire 80 which originates at contact 81 in main switch 31 which when actuated is contacted by pole 34. Lastly the control circuits in lockout switches 59 and 60 of circuit C3 are put in communication with a source of energy by conductor 82 which originates at contact 83 in main switch 32 which is contactable by pole 35.

A second source of power for the control circuits of each of the lock out switches is achieved through conductor 36, wire 89 the contact and pole in each of the switches 56, 58 and 60 and by wires 84, 85 and 86. Accordingly and under sorting conditions later described the lockout switches may be kept energized other than through their main control switches 30-' -32 to prevent actuation of their associated air valve.

From the control circuits of the lockout switches in circuits C1, C2 and C3 conductors 90, 91 and 92 terminate at contacts 93, 94 and 95 in each of the solid state secondary control unit switches 44, 45 and 46 which switches-are operated by amplified signals from their logic modules.

From contacts 64, 70 and 74 in the normally closed lockout switches wires 97, 98 and 99 are in circuit with the control circuit (shown as a coil symbol) for each of the lock in relays 51 52 and 53 said wires each terminating in contact with conductors 90-92. I

Solenoid operated air valves at 100,101, 102 and 103 are in circuit with contacts 108, 109, 110 and '11 of the lock in switches of circuits C1-C4 respectively by wires 104, 105, 106 and 107.

The other contacts 112, 113, 114 and 115 in the lock in switches against which poles 117, 118, 119 and 120 are normally closed serve to power in series via leads 48 and 49 the photoelectriccontrol units with conductors 48 interconnecting fi id poles in series From the foregoing description it will be apparent that to energize one of the solenoid air valves 100-103 the control circuit of its associated lock in switch must be energized through a circuit including main switch 30 (in its normal position), conductor 76, one of the lock out switches 55, 57 and V 59 and a groundconnection at 122,123, 124 or 125 (established by operation of a secondary control unit switch .rupts the beam MB being received'by-photocell receiver which interruption activates the main photoelectric control unit 29 and particularly thelogic module LMl thereof which sends an amplified signal to the three main switches 30, 31am! 32 causing the poles thereof to position oppositely from their normal position shown in FIG. 3. The control circuits (shown as coil symbols) in said switches will remain energized to interrupt or disable the lookout switches 55, 57 and 59 until such time as the trailing end of the carrot passes main beam MB at which time the beam is reestablishedland switches 30, 31 and 32 will return to the normal state as shown.

Upon such reestablishment the control circuits of the lock out switches 55-56 in C1; lockout switches 57-58 in C2 and lockout switches 59-60 in C3 are now set up for closing upon the establishment of acompletion of a circuit to a ground connection at 122, 123 or 124. Such a circuit completion to ground is established for the lock out switches in C1, C2 or C3 by interruption by the leading end of the article of one of the beams B1, B2 or B3 which in turn will actuate respectively its secondary control unit switch 44, 45 o r'46.

A first sorting sequence is now set forth and describes the sorting of a carrot of lesser length than the horizontal distance between beams MB-and B1 as shown in example 1 in FIG. 4.

Upon the trailing end of the carrot passing the beam M8 the poles 33, 34 and 35. of the three main switches will return to their normal position shown in FlG. 3 The carrot nose is not as yet breaking beam B1 so the state of the entire circuit will be as shown in FIG. 3. Upon the carrots leading edge advancing and breaking B1 switch 44 will close to setup a ground at 122 for the control circuit (shown as a coil symbol) of lock'in switch 51 causing pole 117 to close against contact 108. A circuit through pole 117 to the solenoid air valve 100 is now closed which of course will open the solenoid air valve 100 for the lengthened dwell period set intologic module LM2. Such movement of pole 117' will also deactivate the downstream photoelectric control units 41, 42 and 43 for the dwell period during which time the carrot will have passed through their liseconds) it takes the carrot to travel from beam B1 to a diverting zone at DZ adjacent the air nozzles 25-28 the switching will be completed and the airblastfroni nozzle 25 initiated so as to divert the carrot from its normal path into a diverted path as at DP and into a receiver indicated generally at R. The receiver may be in the formshown best in FIG. 2 with diverging surfaces 130 to deflect the carrot into passageways 131 or other means for further transfer of the carrots to additional processing stations.

Assuming now a carrot is of the length shown in example 2. Again the main photoelectric control 29 will be activated during the passage of the carrot through its bearn'MB. As the carrot nose advances and interrupts beam "131 the lock out switches in C1 will be energized through closure of switch 44 providing a ground as previously described. Lockout switch 55 in C1 is opened by its control circuit to prevent lockin switch 51 from being energized. Thus air solenoid 100 is held inactive. Lockout switch 56 serves to set up a second source of power to continue locking out switch 51 even after reestablishment of beam MB upon carrot passage. Thisis accomplished by pole 63 by closing against contact 65 to energize both control circuits of lockout switches 55 and 56. The carrot in example 2is of a length to be sorted or diverted by an air blast from nozzle 26. This is accomplished by the leading edge of the carrot interrupting beam B2 afier the carrots trailing end has cleared main beam MB. With the carrot located as shown in example 2 the main switches 30, 31' and 32 will have returned to their normal position as shown and the C1 lockout switches 55, 56 will be energized locking outair solenoid 100. Interruption, as the carrot advances, of beam B2 will activate switch 45 for a dwell period or set into the control units module which activation completes a circuit to ground for the control circuit of lock in switch 52. Accordingly its pole 118 closes against contact 109 to activate the air solenoid valve 101 to emit an air blast through nozzle .26 for said dwell period. As before, the timing is such that this air blast will be emitted during carrot passage through the diverting zone D2 to divert same along one of the diverted paths DP. Further, and as before, movement of the pole of the lock in switch deactivates all downstream photoelectric controls for the dwell period.

The operation-of circuit C3 is substantially the same as for circuit C2 and hence a description of itsQoperation is not believed necessary to an understanding of the invention. Circuit C3 will operate to sort carrots of a length lesser than the distance between the main beam MB and beam B3 as shown in example 3. will I Circuit C4 will operate to sort those carrots of a length greater than the aforementioned distance such carrots being shown both in-example 4 and 5. lncxamples 4 and 5 and as described in connection with the other examples the three main switches 30-32 will have returned to their normal position as shown in FIG. 3. A second source of power is being ap plied to the lock out switches by reason of switches 56, 58 and 60 holding themselves closed, said second source including conductors 36, 89 and contacts 65, 71 and 75 which source will retain the control circuits of each. lock out switch energized. Thus holding open of contacts 64, and 74 will prevent any actuation of the control circuits of the three lock in switches 51, 52 and 53. With this in mind it will be seen that upon beam B4 being broken the switch 47 is-actuated to close to provide a ground for a circuit including conductor 36, pole 33, contact 77, wire 76 to energize the control circuit of lock in switch 54 which will cause its pole 120 to close against contact 1 l to actuate via line 107 the air solenoid valve 103. Since 1 circuit C4 is the last circuit and hence does not include lock out switches, carrots of a length as in example 5 will trigger an air blast immediately upon its trailing end clearing the main beam MB. It is, believed apparent that the present systems scanning area. No lock out switches are used in this first sequence. With attention to FIG. 1, during-the time (in milcapability for additional like circuits beyond C4 is easily real- 1. An apparatus for the sorting of articles according to a selected dimension of the articles said apparatus comprising:

delivery means consecutively discharging the articles for unsupported travel along a common path to a diverting zone;

a photoelectric scanning system offset from the discharge end of said delivery means and including signal producing components spaced at intervals along and laterally ofiset from the path of the articles, saidcomponents responsive to a passing article;

one of said components being a main signal producing component with the remaining components being secondary components;

control units associated with each of said signal producing components and having signal amplifying means, the control unit associated with said main signal producing component being a main control unit, and the remaining control units being secondary units;

main switch means actuated by said main control unit;

solenoid operated air valves associated with the secondary control units for diverting the articles from their path;

lock in switches each in circuit with one of said solenoid valves;

lock out switch means in circuit with said main switch means the latter operative to disable certain of said lock out switch means during the passage of an article past the main signal producing component;

said main switch means being actuated upon the articles trailing end clearing the main signal producing component to partially complete a first circuit through said lock out switch means and said lock in switch means to energize one of said solenoid air valves; and

secondary control unit operated switch means for completing said first circuit operable upon an amplified signal from a secondary control unit initiated by the leading end of the article being sorted passing one of said secondary signal producing components immediately subsequent to its trailing end clearing the main signal producing component.

2. The sorting apparatus as claimed in claim I wherein said secondary control units also includetneans for lengthening the signal received from said signal producing component.

3. The sorting apparatus as claimed in claim 2 wherein said means for lengthening the amplified signal functions to interrupt the power source to downstream secondary control units.

4. The sorting apparatus as claimed in claim 1 wherein said solenoid operated air valves are in communication with air nozzles disposed adjacently to the path of the articles and which upon actuation of a solenoid operated air valve divert the article by an air blast.

5. The sorting apparatus as claimed in claim 1 wherein said lock out switch means maintains certain of said lock in switches in a deenergized condition after the passage of an article past said main signal producing component. 

